Estimation of readability and document complexity or sophistication is often performed in education and in other domains. Such a situation may occur, for example, where a student or applicant's essay is being scored, or if a document's suitable reading-level (e.g., by school grade level or age) is being determined. These types of determinations are typically performed manually, which are often costly, time-consuming, and lack objectivity. The problem is further exacerbated where the number of documents that need to be analyzed is large.